Throughout much of the world, winter deicing practices have led to secondary salinization of freshwater habitats, where numerous taxa are vulnerable to elevated salinity. Many amphibians are of particular concern because of their permeable skin and reliance on small ponds and pools, where salinity levels can be high. The early life-history stages of amphibians that develop in these habitats are especially sensitive to salt exposure. Larvae developing in salt-polluted environments must osmoregulate through ion exchange in gills. While salt-induced changes to the physiology of ion exchange in amphibian gills is generally understood, functionally relevant changes in gill morphology remain poorly described. Yet the structure of gills should be an important component affecting their ionoregulatory capacity, for instance in terms available surface area. Larval amphibian gills also play critical roles in gas exchange and foraging. Thus, changes in gill morphology due to salt pollution potentially affect not only osmoregulation, but also respiration and feeding. Here, we used a chronic exposure experiment to quantify the effect of salinity on larval gill morphology in populations of the wood frog (Rana sylvatica). We measured a suite of morphological traits on gill tufts, where ionoregulation and gas exchange occur, and on gill filters, which are used in feeding. Larvae raised in high salinity conditions had gill tufts with lower surface area to volume ratio, while epithelial cells on these tufts were less circular but occurred at higher densities. Gill filters showed increased spacing, which can potentially reduce their efficiency in filtering food particles. Together, these changes seem likely to diminish the ionoregulatory and respiratory capacity of gill tufts, and compromise feeding functionality of gill filters. Thus, a singular change in the aquatic environment from a widespread pollutant has the potential to generate a suite of consequences via changes in gill morphology. Critically, this suite of negative effects is likely most detrimental in salinized environments, where ionoregulatory demands are higher, which in turn should increase respiratory demands along with energy acquisition demands through foraging.

中文翻译：

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道路盐损害两栖动物种群中幼虫g的功能形态

在世界上大部分地区，冬季除冰做法导致了淡水生境的二次盐碱化，那里大量的类群易受盐碱化的影响。许多两栖动物特别令人关注，因为它们的皮肤具有渗透性，并且依赖盐度可能很高的小池塘和水池。在这些栖息地中发育的两栖动物的早期生命历史阶段对盐分暴露尤其敏感。在盐污染的环境中发育的幼虫必须通过ion中的离子交换而渗透。虽然人们普遍理解盐诱导的两栖动物g的离子交换生理变化，但仍然很少描述functional形态上功能上相关的变化。然而，ill的结构应该是影响其离子调节能力的重要组成部分，例如在可用表面积方面。幼虫两栖g在气体交换和觅食中也起着关键作用。因此，盐污染造成的g形态改变不仅可能影响渗透压调节，而且还会影响呼吸和进食。在这里，我们使用了一个慢性暴露实验来量化盐度对木蛙（Rana sylvatica）种群中幼虫g形态的影响。我们在发生电离调节和气体交换的g簇以及用于饲养的g滤器上测量了一系列形态特征。在高盐度条件下饲养的幼虫的g簇具有较低的表面积/体积比，而这些簇上的上皮细胞的圆形较少，但密度较高。ill过滤器显示出增加的间距，这可能会降低其过滤食物颗粒的效率。一起，这些变化似乎会降低g簇的电离和呼吸能力，并损害g滤器的进食功能。因此，由广泛的污染物引起的水生环境的单一变化可能会通过g形态的变化产生一系列后果。至关重要的是，这一系列负面影响在盐碱化的环境中可能是最有害的，在盐碱化的环境中，离子调节需求更高，这反过来又会增加觅食带来的呼吸需求以及能量获取需求。